Method of operating electric lamps.



PATENTED NOV. 3, 1903.

V H. N. POTTER. METHOD OF OPERATING ELECTRIC LAMPS.

APPLICATION FILED FEB. 14-, 1901:

N0 MODEL.

INVENTOR 14, M 8%.

WITNESSES: v 6. i m

A T URNEY.

1m: Noam: PEYEFZG c0. Moro-Lama. \wsnmsmu n. c

UNITED STATES Patented November 3, 1903.

PATENT OFFICE,

METHOD OF OPERATING ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 743,396, dated November 3, 1903. Application filed February 14, 1901. Serial No. 47,354. (No model.)

To all whom it may concern:

Be it known that I, HENRY NoEL POTTER, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Methods of Operating Electric Lamps, of which the following is a specification.

In operating electric lamps having glowers that are conductors only when hot and the resistance of which decreases as the temperature increases it is customary to provide each glower with aballast resistance, so as to counteract the decreasing resistance of the glower by an increase in its own resistance as the current through the glower and the ballast increases. I have made use of a ballast resistance composed of a material which has a large corrective effect within a critical region which lies at a comparatively high temperature. One of the materials which I have employed for this purpose is iron wire, so proportioned that it is brought to an approximately dull-red heat by the normal operating-current for the glower. One of the advantages arising from the use of this material is that it may have small weight, and therefore small specific heat, and that it arrives at its temperature of maximum correction quickly on starting up the lamp.

It has been the practice prior to my present invention to place the ballast resistance, of whatever character it may be, in series with the glower, but in shunt to the heater, by means of which the glower is brought to a conductive state. Even with the best ballast resistance when so arranged it sometimes happens that a shooting-over of the current takes place at the initial closure of the lamp-circuit, resulting in injury to the glower. I have discovered that this shooting-over may be avoided by connecting the ballast resistance in the common circuit of the heater and glower or, if connected in shunt to the heater, by locating it in proximity to means for raising its temperature while the temperature of the glower is increased.

The arrangements described possess especial advantages when the ballast resistance responds comparatively slowly to changes in current, as is the case in coiled ballast-conductors. I

Inasmuch as the glower-circuit does not become operative until the heater has raised the glower to a conductive temperature, whereas the heater-circuit begins to operate immediately on the closing of the lamp-circuit, each of my arrangements is such as to insure an increase of the temperature of the ballast-conductor to the desired degree by the time its corrective action on the glower is called into requisition. hen, therefore,the glower begins to take current, the ballast will have already arrived at a temperature at which its resistance increases rapidly with increments of current, whereby the tendency of the current to shoot over and injure or destroy the glower is obviated.

In the accompanying drawings, Figure 1 represents diagrammatically an electric lamp containing the usual glower and heater and the usual cut-out devices, together with my improved ballast resistance located in a circuit common to the glower and heater. Fig. 2 is a similar View of amodified arrangement for effecting substantially the same result.

In Fig. 1 of the drawings, 1 and 2 are mains leading from any suitable generator of electricity. 3 is a ballast resistance consisting of a coil 4 of wire supported by leading-in wires 15 and 16 within a glass bulb 5. 6 is the heater contained in a branch circuit, which includes also the stationary terminals 7 and 8 of an automatic cut-out switch 9. Cooperating with the terminals 7 and 8 are movable terminals 10 and 11, secured to the end of a core 12, which is adapted to move longitudinally within a coil or solenoid 13 in series with a glower 14:. The glower is composed of one or more of the dry electrolytes, such as zirconia yttria or the like, and it has the quality, as is well known, of becoming conductive under the influence of heat, the heat in the first instance being supplied by an external heater, such as 6, and subsequently by the electric current passing through the glower. The glower and the heater are connected up in branch circuits between the mains 1 and 2.

The action of the lamp is as follows: The current passes from the main 1 through the ballast resistance 3, including the coil of iron wire 4, and through the heater 6 and the switch 9 to the opposite main.

The effect of the current is to raise the temperature not only of the heater 6, but also of the iron wire 4. By the time the glower 14 has been brought to a conductive temperature the temperature of the iron wire 4' has been raised to such-a degree that the tendency of the current to rush through the glower is corrected by the rapidly-increasing resistance of the wire 4. The automatic switch or cutout f) operates in the usual Way to break the heater-circuit as soon as the glower-circuit carries enough current to keep the glower incandescent without external heat. The ballast resistance in this arrangement is placed in the common circuit of the heater and glower, and it is by virtue of this placing of the ballast that the glower is protected from an excessive inrush of current on the starting of the lamp.

In the arrangement shown in Fig. 2 the operating parts are in general the same as those shown in Fig. 1, and except as hereinafter specified they are marked by the same reference-numerals and Will not be again described. In this modification the ballastconductor 4: is not connected in circuit with the heater 6, but is located in proximity to a heating device, here shown as a length of Wire 16, forming part of the heater-circuit Within the bulb 3 and of such composition and resistance as to generate the desired degree of heat without being destroyed or materially injured by it.

In order to produce corrective effects by means of the ballast resistance sufficient to counteract the danger of an injurious inrush of the current on the starting of the lamp, it is not necessary to bring the ballast to the temperature at which its greatest corrective effects are present; but it may be sufficient to effect only a slight increase in the temperature of the ballast resistance.

It will be further understood that the temperature of the ballast may be raised other- Wise than as herein specificallyillustrated, since my invention considered in its broadest aspect consists in raising the temperature of the ballast prior to the passage of the glower-current therethrough.

The invention claimed is- 1. The method of protecting lamp-glowers of the type described from an injurious inrush of current on the starting of the lamp, which consists in raising the temperature of a ballast resistance in series with the glower, and automatically inducing therein the condition under which it produces its maximum corrective effect, or approximately so, before the glower has been brought to a conductive state. A

2. The method of protecting lampglowers of the type described from an in j urious'inrush of current on the starting of the lamp, which consists in passing an electric current through a ballast resistance in series With the glower, and automatically inducing therein the condition under which it produces its maximum corrective effect, or approximately so, before the glower has been brought to a conductive state.

The method of protecting lamp-glowers of the type described from an injurious inrush of current on the starting of the lamp, which consists in automatically inducing in the glower-circuit, but external to the glower, a condition adapted to counteract the effects of the decreasing resistance of the glower itself under increments of temperature before the temperature of the glower has been sufficienty raised to render it conductive.

4. The method of operating an electric lamp containing a glower of the type described, which consists in automatically inducing in the external circuit of the glower a condition adapted to cause rapid increases of resistance with increments of current and afterward causing the glower to attain a state of conductivity.

5. The method of operating an electric lamp containing a glower of the'type described in series With a ballast resistance having a hightemperature coefficient,which consists in first raising the temperature of the said ballast resistance above the normal and afterward bringing the glower to a conductive temperature.

In testimony whereof I have hereunto subscribed my name this 8th day of February, 1901.

HENRY NOEL POTTER.

IVitnesses:

JAMES B. YOUNG, iVEsLEY G. CARR. 

